Gold Nanoparticle Conjugates and Uses Thereof

ABSTRACT

The disclosure generally relates to formation of polymers grafted to or polymerized from the surface of gold nanoparticles. The polymers are functionalized to include therapeutic agents and/or targeting agents at their surface, thereby allowing both therapeutic and targeting compounds to be directed to specific cells in a patient.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 12/197,044, entitled “Gold Nanoparticle Conjugates and UsesThereof,” filed Aug. 22, 2008, which claims the benefit of priorityunder 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/957,208entitled “Gadolinium and Gold Nanoparticle Conjugates and Uses Thereof,”filed Aug. 22, 2007, each of which is hereby incorporated by referencein its entirety. This application is also related to U.S. patentapplication Ser. No. 12/197,061 entitled “Lanthanide NanoparticleConjugates and Uses Thereof,” filed Aug. 22, 2008, which has issued asU.S. Pat. No. 8,916,135, and to co-pending U.S. patent application Ser.No. 14/580,827, entitled “Lanthanide Nanoparticle Conjugates and UsesThereof,” filed Dec. 23, 2014, each of which is hereby incorporated byreference in its entirety.

FIELD

The disclosure generally relates to formation of polymers grafted to orpolymerized from the surface of gold nanoparticles. The polymers arefunctionalized to include therapeutic agents and targeting agents attheir surface, thereby allowing both imaging and targeting therapeuticcompounds to specific cells in a patient.

BACKGROUND

One of the most important areas of research in the general field ofnanotechnology is in the development of nanomedicines, which refers tohighly specific medical intervention at the molecular scale fordiagnosis, prevention, and treatment of diseases. See, e.g. Park, K. J.Controlled Release 2007, 120, 1-3. The importance of this area ishighlighted by the recent establishment of the National Institutes ofHealth (NIH) Nanomedicine Roadmap Initiative(http://nihroadmap.nih.gov/nanomedicine/), where over $1 billion hasbeen committed in an attempt to revolutionize the areas of therapeuticsand diagnostics through the development and application ofnanotechnology and nanodevices. One of the most exciting areas ofnanomedicine is the development of nanodevices for theragnostics, whichrefers to a combination of diagnostics and therapeutics for tailoredtreatment of diseases. The synthesis of nanodevices that incorporatetherapeutic agents, molecular targeting, and diagnostic imagingcapabilities have been described as the next generation nanomedicinesand have the potential to dramatically improve the therapeutic outcomeof drug therapy (e.g. Nasongkla, N. et al. Nano Lett. 2006, 6,2427-2430) and lead to the development of personalized medicine, wherethe device may be tailored for treatment of individual patients on thebasis of their genetic profiles. While there is almost unanimousagreement in the scientific community that these next generationnanomedicines will provide clinically important theragnosis devices,they have yet to be clinically realized.

One of the primary reasons for this is the poor design and manufacturingtechniques of the current nanodevices. The main problems with thecurrent manufacturing techniques include low drug and/or targetingmoiety loading capacity, low loading efficiencies, and poor ability tocontrol the size distribution, surface interactions, and in vivoperformance of the devices. See, e.g., Park, K. J. Controlled Release2007, 120, 1-3. In conjunction to these manufacturing problems, currentdesign issues center around a lack of flexibility in the construct whichmay limit the type and quantity of drug and/or targeting agent that maybe incorporated, provide little or no control over spatial orientationand architecture of the nanoparticle, and have stability issues with theparticle structure or with the drug and/or targeting agent incorporatedin the particle.

Recently polymer-based nanodevices have received much attention and manybelieve that they are the most promising for clinical translation. See,e.g., Bridot, J.-L., et al. J. Am. Chem. Soc. 2007. Examples ofpolymer-based theragnostic nanodevices includes dendrimers, polymericmicelles, and polymer-based core-shell nanoparticles. While dendrimershave proven to be effective for drug delivery or targeted molecularimaging, it is difficult to control the loading capacity and efficiencyof the drug, imaging and/or targeting agent. Polymeric micelles use ahydrophobic core to carry therapeutics and imaging agents, whiletargeting agents are attached to the hydrophilic corona. However,micelle structures are susceptible to instabilities due to changes inthe surrounding in vivo environment and have limited control of loadingcapacity. Polymer-based core-shell nanoparticles offer improvedstability over polymer micelles; however, it is often difficult torelease therapeutic agents contained within the core of the structurewhich tends to inhibit their therapeutic value.

One area that has reached significant commercial application is the useof targeted drug delivery. This represents an extremely diverse area dueto the large number of diseases that potentially benefit from targeteddelivery. As the current focus of research into the invention has beenon the targeted imaging and treatment of cancer, this discussion willfocus on competitive products in the areas of cancer therapy anddiagnosis. However, the flexibility of the invention allows for itspotential use in any disease that would benefit from theragnosis.

The present disclosure has been developed against this backdrop.

SUMMARY

The present disclosure is directed generally to gold nanoparticleconjugates, particularly to polymers, and the subsequent conjugation totargeting agents and therapeutic agents, and their use in targeting,treating, and/or imaging disease states in a patient. In certainembodiments, the gold nanoparticle conjugates are multifunctionalpolymeric systems. Biocompatible polymer backbones that can beconjugated to imaging agents, targeting agents, and therapeutic agentsare produced. Post-polymerization modification of the polymer backboneallows attachment of targeting agents or therapeutic agents to afunctional group. The resulting gold nanoparticle conjugates provide theability to target, treat, and image diseased cells.

In one aspect, gold nanoparticle conjugates are provided. The conjugateincludes a gold nanoparticle and a polymer or polymer precursorcontaining a functional group attached to the nanoparticle. As usedherein, polymer precursors include components of polymers, such asmonomers, dimers, etc., or initiators bonded to the gold nanoparticleprior to polymerization. In various aspects, the functional group isselected from the group consisting of thiolates, thioethers, thioesters,carboxylates, amines, amides, halides, phosphonates, phosphonate esters,phosphinates, sulphonates, sulphates, porphyrins, nitrates, pyridine,pyridyl based compounds, nitrogen containing ligands, oxygen containingligands, and sulfur containing ligands. In certain embodiments, thepolymer, polymer precursor or initiator can be grafted onto the goldnanoparticle by a covalent or non-covalent bond between a functionalgroup and nanoparticle. In certain embodiments, the functional group isa single thiol group and vacant orbital present on the gold (III)cation. In further aspects, the gold nanoparticle conjugate can have thechemical structure according to formulae (I) or (II):

wherein n is an integer,

R₁, R₂, R₃, and R₄ are each independently selected from hydrogen, alkyl,substituted alkyl, alkoxy, substituted alkoxy, acyl, substituted acyl,acylamino, substituted acylamino, alkylamino, substituted alkylamino,alkylsulfinyl, substituted alkylsulfinyl, alkylsulfonyl, substitutedalkylsulfonyl, alkylthio, substituted alkylthio, alkoxycarbonyl,substituted alkoxycarbonyl, aryl, substituted aryl, arylalkyl,substituted arylalkyl, aryloxy, substituted aryloxy, aryloxycarbonyl,substituted aryloxycarbonyl, carbamoyl, substituted carbamoyl,cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substitutedcycloheteroalkyl, dialkylamino, substituted dialkylamino, halo,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, heteroarylalkyl, substituted heteroarylalkyl,heteroalkyloxy, substituted heteroalkyloxy, heteroaryloxy andsubstituted heteroaryloxy.

In other embodiments, R₂ includes a functional group selected fromthiolates, thioethers, thioesters, carboxylates, amines, amides,halides, phosphonates, phosphonate esters, phosphinates, sulphonates,sulphates, porphyrins, nitrates, pyridine, pyridyl based compounds,nitrogen containing ligands, oxygen containing ligands, and sulfurcontaining ligands.

The polymer portion of the nanoparticle conjugate can include adithioester, trithiocarbonate, xanthate, or dithiocarbamate chaintermination agent, and/or a functional group such as carboxylic acidsand carboxylic acid salt derivatives, acid halides, sulfonic acids andsulfonic acid salts, anhydride derivatives, hydroxyl derivatives, amineand amide derivatives, silane derivations, phosphate derivatives, nitroderivatives, succinimide and sulfo-containing succinimide derivatives,halide derivatives, alkene derivatives, morpholine derivatives, cyanoderivatives, epoxide derivatives, ester derivatives, carbazolederivatives, azide derivatives, alkyne derivatives, acid containingsugar derivatives, glycerol analogue derivatives, maleimide derivatives,protected acids and alcohols, and acid halide derivatives. The goldnanoparticle conjugate can further include a therapeutic agent and/or atargeting agent, each covalently bonded to said polymer.

In another aspect, the disclosure is directed to a pharmaceuticalcomposition comprising the gold nanoparticle conjugate as describedherein, and a pharmaceutically acceptable carrier.

In a further aspect, the disclosure is directed to a method of makinggold nanoparticle conjugates. A gold nanoparticle having a suitableinitiator is contacted with a dithioester, xanthate, or dithiocarbamateof formulae (III) or a trithiocarbonate of formulae (IV):

whereinR₅, R₆, R₇, and R₈ are each independently selected from hydrogen, alkyl,substituted alkyl, alkoxy, substituted alkoxy, acyl, substituted acyl,acylamino, substituted acylamino, alkylamino, substituted alkylamino,alkylsulfinyl, substituted alkylsulfinyl, alkylsulfonyl, substitutedalkylsulfonyl, alkylthio, substituted alkylthio, alkoxycarbonyl,substituted alkoxycarbonyl, aryl, substituted aryl, arylalkyl,substituted arylalkyl, aryloxy, substituted aryloxy, aryloxycarbonyl,substituted aryloxycarbonyl, carbamoyl, substituted carbamoyl,cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substitutedcycloheteroalkyl, dialkylamino, substituted dialkylamino, halo,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, heteroarylalkyl, substituted heteroarylalkyl,heteroalkyloxy, substituted heteroalkyloxy, heteroaryloxy andsubstituted heteroaryloxy.

In other embodiments, R₆ and R₈ are each independently selected from adithioester, xanthate, dithiocarbamate and trithiocarbonate. Thecompounds of formulae (III) and (IV) are contacted with a reducingagent. The reduced compounds are then contacted with a gold nanoparticleto form a gold nanoparticle conjugate.

In further aspects, the disclosure is directed to a method of treating adisease or disorder by administering a gold nanoparticle conjugate to apatient in need of treatment of said disease or disorder. In variousembodiments, the targeting agent localizes the nanoparticle conjugate tothe site of the disease or disorder. The therapeutic agent treats saiddisease or disorder. The method can be further combined with imaging thegold nanoparticle conjugate at the disease location.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed Figures are exemplary, and are not intended to be limitingof the claims.

FIG. 1 depicts transmission electron microscope (TEM) images of variousexemplary gold nanorod structures.

FIG. 2 depicts an exemplary protocol for seeding a gold nanorod.

FIG. 3 depicts a group of gold nanorods that have been seeded accordingto the method depicted in FIG. 2.

FIG. 4 depicts a comparison absorbance spectrum of A) gold nanorods, B)gold nanorods modified with the strong reducing agent sodium borohydrideand poly(acrylic acid) (PAA) and C) gold nanorods modified with PAA andwithout sodium borohydride.

FIGS. 5 a and 5 b depict TEM images of gold nanorod modified by PAAafter treatment with sodium borohydride and without sodium borohydride.

FIG. 6 depicts a comparison absorbance spectrum of A) gold nanorods, B)gold nanorods modified with the strong reducing agent sodium borohydrideand (PMMA)-b-poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA), and C)gold nanorods modified with PDMAEMA and without sodium borohydride.

FIGS. 7 a and 7 b depict TEM images of a gold nanorod modified bypoly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) after treatment withsodium borohydride and without sodium borohydride.

FIG. 8 depicts a comparison absorbance spectrum of A) gold nanorods, B)gold nanorods modified with the strong reducing agent sodium borohydrideand polystyrene (PS) and C) gold nanorods modified with PS and withoutsodium borohydride.

FIGS. 9 a and 9 b depict TEM images of a gold nanorod modified byPDMAEMA after treatment with sodium borohydride and without sodiumborohydride.

FIG. 10 a depicts a ¹H NMR spectrum of PNIPAM-co-PNAOS-co-PFMAcopolymer. FIG. 10 b depicts a ¹H NMR spectrum of folic acid. FIG. 10 cdepicts a ¹H NMR spectrum of PNIPAM copolymer reacted with folic acid.

FIG. 11 depicts the mushroom to brush spatial transition of polymers ata surface.

FIG. 12 depicts generating a polymer by grafting a polymer from apolymer precursor M at the surface of the bound polymer.

FIG. 13 depicts exemplary targeting molecules (folic acid or an RGDsequence) and exemplary therapeutic agents (the cancer therapeuticspaclitaxel or methotrexate) binding to a functionalized polymer graftedto a nanoparticle.

DETAILED DESCRIPTION

There has been an increasing focus on the development of multifunctionalnanomedicines for improvement in the remedial results of drug treatmentfor cancer patients. See, e.g., Kukowska-Latallo, J. F. et al., Langmuir2004, 20, 6414-6420, Niidome, T. et al. Journal of Controlled Release2006, 114, 343-347. Multifunctional nanomedicines incorporate diagnosticimaging capabilities, targeting through biomolecular recognition, and atherapeutic agent for treatment of a specific disease, providing a “onedose” approach of overcoming downfalls of conventional treatment andimaging techniques.

The present disclosure relates to preparation of gold nanoparticleconjugates comprising a gold nanoparticle grafted onto a polymer orpolymer precursor comprising a functional group. The functional groupserves as the point of attachment to the gold nanoparticle. Thus,molecules are specifically bonded to gold nanoparticles by a specificfunctional group. The nanoparticle conjugates are then furtherfunctionalized to include a therapeutic and/or diagnostic agent.

DEFINITIONS

A dash (“-”) that is not between two letters or symbols is used toindicate a point of attachment for a moiety or substituent. For example,—CONH₂ is attached through the carbon atom.

“Grafting” or “grafted onto” as used herein refers to attaching apolymer, polymer precursor or small molecule to the surface of ananoparticle via a single functional group. Grafting includes bothcovalent and non-covalent binding, as well as, but not limited to,delocalized bond formation between one or more atoms of the nanoparticleand one or more atoms of the functional group, ionic bonding, hydrogenbonding, dipole-dipole bonding, and van der Waals forces. Formation ofexemplary bonds are depicted in Schemes 2 and 3 described herein. Theterms “grafting” and “grafting onto” include methods conventionallyreferred to as grafting from and grafting to.

“Covalent grafting” as used herein refers to attaching a polymer,polymer precursor, or small molecule by one or more covalent bonds froma functional group to the surface of a nanoparticle or by a delocalizedbond complex, such as a delocalized bond complex.

“Alkyl” by itself or as part of another substituent refers to asaturated or unsaturated, branched, straight-chain or cyclic monovalenthydrocarbon radical derived by the removal of one hydrogen atom from asingle carbon atom of a parent alkane, alkene or alkyne. Typical alkylgroups include, but are not limited to, methyl; ethyls such as ethanyl,ethenyl, ethynyl; propyls such as propan-1-yl, propan-2-yl,cyclopropan-1-yl, prop-1-en-1-yl, prop-1-en-2-yl, prop-2-en-1-yl(allyl),cycloprop-1-en-1-yl; cycloprop-2-en-1-yl, prop-1-yn-1-yl,prop-2-yn-1-yl, etc.; butyls such as butan-1-yl, butan-2-yl,2-methyl-propan-1-yl, 2-methyl-propan-2-yl, cyclobutan-1-yl,but-1-en-1-yl, but-1-en-2-yl, 2-methyl-prop-1-en-1-yl, but-2-en-1-yl,but-2-en-2-yl, buta-1,3-dien-1-yl, buta-1,3-dien-2-yl,cyclobut-1-en-1-yl, cyclobut-1-en-3-yl, cyclobuta-1,3-dien-1-yl,but-1-yn-1-yl, but-1-yn-3-yl, but-3-yn-1-yl, etc.; and the like.

The term “alkyl” is specifically intended to include groups having anydegree or level of saturation, i.e., groups having exclusively singlecarbon-carbon bonds, groups having one or more double carbon-carbonbonds, groups having one or more triple carbon-carbon bonds and groupshaving mixtures of single, double and triple carbon-carbon bonds. Wherea specific level of saturation is intended, the expressions “alkanyl,”“alkenyl,” and “alkynyl” are used. In certain embodiments, an alkylgroup can have from 1 to 20 carbon atoms (C₁₋₂₀) in certain embodiments,from 1 to 10 carbon atoms (C₁₋₁₀), in certain embodiments from 1 to 8carbon atoms (C₁₋₈), in certain embodiments, from 1 to 6 carbon atoms(C₁₋₆), in certain embodiments from 1 to 4 carbon atoms (C₁₋₄), and incertain embodiments, from 1 to 3 carbon atoms (C₁₋₃).

“Alkanyl” by itself or as part of another substituent refers to asaturated branched, straight-chain or cyclic alkyl radical derived bythe removal of one hydrogen atom from a single carbon atom of a parentalkane. Typical alkanyl groups include, but are not limited to,methanyl; ethanyl; propanyls such as propan-1-yl,propan-2-yl(isopropyl), cyclopropan-1-yl, etc.; butanyls such asbutan-1-yl, butan-2-yl(sec-butyl), 2-methyl-propan-1-yl(isobutyl),2-methyl-propan-2-yl(t-butyl), cyclobutan-1-yl, etc.; and the like.

“Alkenyl” by itself or as part of another substituent refers to anunsaturated branched, straight-chain or cyclic alkyl radical having atleast one carbon-carbon double bond derived by the removal of onehydrogen atom from a single carbon atom of a parent alkene. The groupmay be in either the cis or trans conformation about the double bond(s).Typical alkenyl groups include, but are not limited to, ethenyl;propenyls such as prop-1-en-1-yl, prop-1-en-2-yl, prop-2-en-1-yl(allyl),prop-2-en-2-yl, cycloprop-1-en-1-yl; cycloprop-2-en-1-yl; butenyls suchas but-1-en-1-yl, but-1-en-2-yl, 2-methyl-prop-1-en-1-yl, but-2-en-1-yl,but-2-en-1-yl, but-2-en-2-yl, buta-1,3-dien-1-yl, buta-1,3-dien-2-yl,cyclobut-1-en-1-yl, cyclobut-1-en-3-yl, cyclobuta-1,3-dien-1-yl, etc.;and the like.

“Alkynyl” by itself or as part of another substituent refers to anunsaturated branched, straight-chain or cyclic alkyl radical having atleast one carbon-carbon triple bond derived by the removal of onehydrogen atom from a single carbon atom of a parent alkyne. Typicalalkynyl groups include, but are not limited to, ethynyl; propynyls suchas prop-1-yn-1-yl, prop-2-yn-1-yl, etc.; butynyls such as but-1-yn-1-yl,but-1-yn-3-yl, but-3-yn-1-yl, etc.; and the like.

“Acyl” by itself or as part of another substituent refers to a radical—C(O)R³⁰, where R³⁰ is hydrogen, alkyl, cycloalkyl, cycloheteroalkyl,aryl, arylalkyl, heteroalkyl, heteroaryl or heteroarylalkyl as definedherein. Representative examples include, but are not limited to formyl,acetyl, cyclohexylcarbonyl, cyclohexylmethylcarbonyl, benzoyl,benzylcarbonyl and the like.

“Acylamino” by itself or as part of another substituent refers to aradical —NR³¹C(O)R³², where R³¹ and R³² are independently hydrogen,alkyl, cycloalkyl, cycloheteroalkyl, aryl, arylalkyl, heteroalkyl,heteroaryl or heteroarylalkyl as defined herein. Representative examplesinclude, but are not limited to formamido, acetamido and benzamido.

“Acyloxy” by itself or as part of another substituent refers to aradical —OC(O)R³³, where R³³ is alkyl, cycloalkyl, cycloheteroalkyl,aryl, arylalkyl, heteroalkyl, heteroaryl or heteroarylalkyl as definedherein. Representative examples include, but are not limited to acetoxy,isobutyroyloxy, benzoyloxy, phenylacetoxy and the like.

“Alkoxy” by itself or as part of another substituent refers to a radical—OR³⁴ where R³⁴ represents an alkyl or cycloalkyl group as definedherein. Representative examples include, but are not limited to,methoxy, ethoxy, propoxy, butoxy, cyclohexyloxy and the like.

“Alkylamino” means a radical —NHR where R represents an alkyl orcycloalkyl group as defined herein. Representative examples include, butare not limited to, methylamino, ethylamino, 1-methylethylamino,cyclohexyl amino and the like.

“Alkoxycarbonyl” by itself or as part of another substituent refers to aradical —C(O)—OR³⁶ where R³⁵ represents an alkyl or cycloalkyl group asdefined herein. Representative examples include, but are not limited to,methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl,cyclohexyloxycarbonyl and the like.

“Alkoxycarbonylamino” by itself or as part of another substituent refersto a radical —NR³⁶C(O)—OR³⁷ where R³⁶ represents an alkyl or cycloalkylgroup and R³⁷ is alkyl, cycloalkyl, cycloheteroalkyl, aryl, arylalkyl,heteroalkyl, heteroaryl, heteroarylalkyl as defined herein.Representative examples include, but are not limited to,methoxycarbonylamino, tert-butoxycarbonylamino andbenzyloxycarbonylamino.

“Alkoxycarbonyloxy” by itself or as part of another substituent refersto a radical —OC(O)—OR³⁸ where R³⁸ represents an alkyl or cycloalkylgroup as defined herein. Representative examples include, but are notlimited to, methoxycarbonyloxy, ethoxycarbonyloxy andcyclohexyloxycarbonyloxy.

“Alkylsulfinyl” refers to a radical —S(O)R where R is an alkyl orcycloalkyl group as defined herein. Representative examples include, butare not limited to, methylsulfinyl, ethylsulfinyl, propylsulfinyl,butylsulfinyl and the like.

“Alkylsulfonyl” refers to a radical —S(O)₂R where R is an alkyl orcycloalkyl group as defined herein. Representative examples include, butare not limited to, methylsulfonyl, ethylsulfonyl, propylsulfonyl,butylsulfonyl and the like.

“Alkylthio” refers to a radical —SR where R is an alkyl or cycloalkylgroup as defined herein that may be optionally substituted as definedherein. Representative examples include, but are not limited tomethylthio, ethylthio, propylthio, butylthio and the like.

“Aryl” by itself or as part of another substituent refers to amonovalent aromatic hydrocarbon radical derived by the removal of onehydrogen atom from a single carbon atom of a parent aromatic ringsystem. Typical aryl groups include, but are not limited to, groupsderived from aceanthrylene, acenaphthylene, acephenanthrylene,anthracene, azulene, benzene, chrysene, coronene, fluoranthene,fluorene, hexacene, hexaphene, hexalene, as-indacene, s-indacene,indane, indene, naphthalene, octacene, octaphene, octalene, ovalene,penta-2,4-diene, pentacene, pentalene, pentaphene, perylene, phenalene,phenanthrene, picene, pleiadene, pyrene, pyranthrene, rubicene,triphenylene, trinaphthalene and the like. In some embodiments, an arylgroup is from 6 to 20 carbon atoms. In other embodiments, an aryl groupis from 6 to 12 carbon atoms.

“Arylalkyl” by itself or as part of another substituent refers to anacyclic alkyl radical in which one of the hydrogen atoms bonded to acarbon atom, typically a terminal or sp³ carbon atom, is replaced withan aryl group. Typical arylalkyl groups include, but are not limited to,benzyl, 2-phenylethan-1-yl, 2-phenylethen-1-yl, naphthylmethyl,2-naphthylethan-1-yl, 2-naphthylethen-1-yl, naphthobenzyl,2-naphthophenylethan-1-yl and the like. Where specific alkyl moietiesare intended, the nomenclature arylalkanyl, arylalkenyl and/orarylalkynyl is used. In some embodiments, an arylalkyl group is (C₆-C₃₀)arylalkyl, e.g., the alkanyl, alkenyl or alkynyl moiety of the arylalkylgroup is (C₁-C₁₀) and the aryl moiety is (C₆-C₂₀). In other embodiments,an arylalkyl group is (C₆-C₂₀) arylalkyl, e.g., the alkanyl, alkenyl oralkynyl moiety of the arylalkyl group is (C₁-C₈) and the aryl moiety is(C₆-C₁₂).

“Aryloxycarbonyl” refers to a radical —C(O)—O-aryl where aryl is asdefined herein.

“Aryloxy” refers to a radical —C—O-aryl where aryl is as defined herein.

“Carbamoyl” by itself or as part of another substituent refers to theradical —C(O)NR³⁹R⁴⁰ where R³⁹ and R⁴⁰ are independently hydrogen,alkyl, cycloalkyl or aryl as defined herein.

“Carbamoyloxy” by itself or as part of another substituent refers to theradical —OC(O)NR⁴¹R⁴² where R⁴¹ and R⁴² are independently hydrogen,alkyl, cycloalkyl or aryl as defined herein.

“Compounds” of as defined by a chemical formula as disclosed hereininclude any specific compounds within the formula. Compounds may beidentified either by their chemical structure and/or chemical name. Whenthe chemical structure and chemical name conflict, the chemicalstructure is determinative of the identity of the compound. Thecompounds described herein may comprise one or more chiral centersand/or double bonds and therefore may exist as stereoisomers such asdouble-bond isomers (i.e., geometric isomers), enantiomers, ordiastereomers. Accordingly, any chemical structures within the scope ofthe specification depicted, in whole or in part, with a relativeconfiguration encompass all possible enantiomers and stereoisomers ofthe illustrated compounds including the stereoisomerically pure form(e.g., geometrically pure, enantiomerically pure, or diastereomericallypure) and enantiomeric and stereoisomeric mixtures. Enantiomeric andstereoisomeric mixtures may be resolved into their component enantiomersor stereoisomers using separation techniques or chiral synthesistechniques well known to the skilled artisan.

Compounds include, but are not limited to, optical isomers of compounds,racemates thereof, and other mixtures thereof. In such embodiments, thesingle enantiomers or diastereomers, i.e., optically active forms, canbe obtained by asymmetric synthesis or by resolution of the racemates.Resolution of the racemates may be accomplished, for example, byconventional methods such as crystallization in the presence of aresolving agent, or chromatography, using, for example a chiralhigh-pressure liquid chromatography (HPLC) column. In addition,compounds can include Z- and E-forms (or cis- and trans-forms) ofcompounds with double bonds.

Compounds may also include isotopically labeled compounds where one ormore atoms have an atomic mass different from the atomic massconventionally found in nature. Examples of isotopes that may beincorporated into the compounds disclosed herein include, but are notlimited to, ²H, ³H, ¹¹C, ¹³C, ¹⁴C, ¹⁵N, ¹⁸O, ¹⁷O, etc. Compounds mayexist in unsolvated forms as well as solvated forms, including hydratedforms and as N-oxides. In general, compounds as referred to herein maybe free acid, hydrated, solvated, or N-oxides of a Formula. Certaincompounds may exist in multiple crystalline, co-crystalline, oramorphous forms. Compounds include pharmaceutically acceptable saltsthereof, or pharmaceutically acceptable solvates of the free acid formof any of the foregoing, as well as crystalline forms of any of theforegoing.

“Pharmaceutically acceptable salt” refers to a salt of a compound, whichpossesses the desired pharmacological activity of the parent compound.Such salts include acid addition salts, formed with inorganic acids suchas hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid,phosphoric acid, and the like; or formed with organic acids such asacetic acid, propionic acid, hexanoic acid, cyclopentanepropionic acid,glycolic acid, pyruvic acid, lactic acid, malonic acid, succinic acid,malic acid, maleic acid, fumaric acid, tartaric acid, citric acid,benzoic acid, 3-(4-hydroxybenzoyl)benzoic acid, cinnamic acid, mandelicacid, methanesulfonic acid, ethanesulfonic acid, 1,2-ethane-disulfonicacid, 2-hydroxyethanesulfonic acid, benzenesulfonic acid,4-chlorobenzenesulfonic acid, 2-naphthalenesulfonic acid,4-toluenesulfonic acid, camphorsulfonic acid,4-methylbicyclo[2.2.2]-oct-2-ene-1-carboxylic acid, glucoheptonic acid,3-phenylpropionic acid, trimethylacetic acid, tertiary butylacetic acid,lauryl sulfuric acid, gluconic acid, glutamic acid, hydroxynaphthoicacid, salicylic acid, stearic acid, muconic acid, and the like; andsalts formed when an acidic proton present in the parent compound isreplaced by a metal ion, e.g., an alkali metal ion, an alkaline earthion, or an aluminum ion; or coordinates with an organic base such asethanolamine, diethanolamine, triethanolamine, N-methylglucamine, andthe like. In certain embodiments, a pharmaceutically acceptable salt isthe hydrochloride salt. In certain embodiments, a pharmaceuticallyacceptable salt is the sodium salt.

“Salt” refers to a salt of a compound, including, but not limited to,pharmaceutically acceptable salts.

“Pharmaceutically acceptable vehicle” refers to a pharmaceuticallyacceptable diluent, a pharmaceutically acceptable adjuvant, apharmaceutically acceptable excipient, a pharmaceutically acceptablecarrier, or a combination of any of the foregoing with which a compoundprovided by the present disclosure may be administered to a patient andwhich does not destroy the pharmacological activity thereof and which isnon-toxic when administered in doses sufficient to provide atherapeutically effective amount of the compound.

“Pharmaceutical composition” refers to a compound of Formula (I) orFormula (II) and at least one pharmaceutically acceptable vehicle, withwhich the compound of Formula (I) or Formula (II) is administered to apatient.

“Solvate” refers to a molecular complex of a compound with one or moresolvent molecules in a stoichiometric or non-stoichiometric amount. Suchsolvent molecules are those commonly used in the pharmaceutical art,which are known to be innocuous to a patient, e.g., water, ethanol, andthe like. A molecular complex of a compound or moiety of a compound anda solvent can be stabilized by non-covalent intra-molecular forces suchas, for example, electrostatic forces, van der Waals forces, or hydrogenbonds. The term “hydrate” refers to a solvate in which the one or moresolvent molecules is water.

“Conjugate acid of an organic base” refers to the protonated form of aprimary, secondary or tertiary amine or heteroaromatic nitrogen base.Representative examples include, but are not limited to,triethylammonium, morpholinium and pyridinium.

“Cycloalkyl” by itself or as part of another substituent refers to asaturated or unsaturated cyclic alkyl radical. Where a specific level ofsaturation is intended, the nomenclature “cycloalkanyl” or“cycloalkenyl” is used. Typical cycloalkyl groups include, but are notlimited to, groups derived from cyclopropane, cyclobutane, cyclopentane,cyclohexane and the like. In some embodiments, the cycloalkyl group is(C₃-C₁₀)cycloalkyl. In other embodiments, the cycloalkyl group is(C₃-C₇)cycloalkyl.

“Cycloheteroalkyl” by itself or as part of another substituent refers toa saturated or unsaturated cyclic alkyl radical in which one or morecarbon atoms (and any associated hydrogen atoms) are independentlyreplaced with the same or different heteroatom. Typical heteroatoms toreplace the carbon atom(s) include, but are not limited to, N, P, O, S,Si, etc. Where a specific level of saturation is intended, thenomenclature “cycloheteroalkanyl” or “cycloheteroalkenyl” is used.Typical cycloheteroalkyl groups include, but are not limited to, groupsderived from epoxides, azirines, thiiranes, imidazolidine, morpholine,piperazine, piperidine, pyrazolidine, pyrrolidine, quinuclidine, and thelike.

“Dialkylamino” by itself or as part of another substituent refers to theradical —NR⁴³R⁴⁴ where R⁴³ and R⁴⁴ are independently alkyl, cycloalkyl,cycloheteroalkyl, arylalkyl, heteroalkyl or heteroarylalkyl, oroptionally R⁴³ and R⁴⁴ together with the nitrogen to which they areattached form a cycloheteroalkyl ring.

“Heteroalkyl, Heteroalkanyl, Heteroalkenyl and Heteroalkynyl” bythemselves or as part of another substituent refer to alkyl, alkanyl,alkenyl and alkynyl groups, respectively, in which one or more of thecarbon atoms (and any associated hydrogen atoms) are independentlyreplaced with the same or different heteroatomic groups. Typicalheteroatomic groups which can be included in these groups include, butare not limited to, —O—, —S—, —O—O—, —S—S—, —O—S—, —NR⁴⁵R⁴⁶, —N—N—,—N═N—, —N═N—NR⁴⁷R⁴⁸, —PR⁴⁹—, —P(O)₂—, —POR⁵⁰—, —O—P(O)₂—, —SO—, —SO₂—,—SnR⁵¹R⁵²— and the like, where R⁴⁵, R⁴⁶, R⁴⁷, R⁴⁸, R⁴⁹, R⁵⁰, R⁵¹ and R⁵²are independently hydrogen, alkyl, substituted alkyl, aryl, substitutedaryl, arylalkyl, substituted arylalkyl, cycloalkyl, substitutedcycloalkyl, cycloheteroalkyl, substituted cycloheteroalkyl, heteroalkyl,substituted heteroalkyl, heteroaryl, substituted heteroaryl,heteroarylalkyl or substituted heteroarylalkyl.

“Heteroaryl” by itself or as part of another substituent refers to amonovalent heteroaromatic radical derived by the removal of one hydrogenatom from a single atom of a parent heteroaromatic ring system. Typicalheteroaryl groups include, but are not limited to, groups derived fromacridine, arsindole, carbazole, β-carboline, chromane, chromene,cinnoline, furan, imidazole, indazole, indole, indoline, indolizine,isobenzofuran, isochromene, isoindole, isoindoline, isoquinoline,isothiazole, isoxazole, naphthyridine, oxadiazole, oxazole, perimidine,phenanthridine, phenanthroline, phenazine, phthalazine, pteridine,purine, pyran, pyrazine, pyrazole, pyridazine, pyridine, pyrimidine,pyrrole, pyrrolizine, quinazoline, quinoline, quinolizine, quinoxaline,tetrazole, thiadiazole, thiazole, thiophene, triazole, xanthene, and thelike. Preferably, the heteroaryl group is from 5-20 membered heteroaryl,more preferably from 5-10 membered heteroaryl. Certain heteroaryl groupsare those derived from thiophene, pyrrole, benzothiophene, benzofuran,indole, pyridine, quinoline, imidazole, oxazole and pyrazine

“Heteroarylalkyl” by itself or as part of another substituent refers toan acyclic alkyl radical in which one of the hydrogen atoms bonded to acarbon atom, typically a terminal or sp³ carbon atom, is replaced with aheteroaryl group. Where specific alkyl moieties are intended, thenomenclature heteroarylalkanyl, heteroarylalkenyl and/orheterorylalkynyl is used. In some embodiments, the heteroarylalkyl groupis a 6-30 membered heteroarylalkyl, e.g., the alkanyl, alkenyl oralkynyl moiety of the heteroarylalkyl is 1-10 membered and theheteroaryl moiety is a 5-20-membered heteroaryl. In other embodiments,the heteroarylalkyl group is a 6-20 membered heteroarylalkyl, e.g., thealkanyl, alkenyl or alkynyl moiety of the heteroarylalkyl is 1-8membered and the heteroaryl moiety is a 5-12-membered heteroaryl.

“Sulfonamido” by itself or as part of another substituent refers to aradical —NR⁵³S(O)₂R⁵⁴, where R⁵³ is alkyl, substituted alkyl,cycloalkyl, cycloheteroalkyl, aryl, substituted aryl, arylalkyl,heteroalkyl, heteroaryl or heteroarylalkyl and R⁵⁴ is hydrogen, alkyl,cycloalkyl, cycloheteroalkyl, aryl, arylalkyl, heteroalkyl, heteroarylor heteroarylalkyl as defined herein. Representative examples include,but are not limited to methanesulfonamido, benzenesulfonamido andp-toluenesulfonamido.

“Aromatic Ring System” by itself or as part of another substituentrefers to an unsaturated cyclic or polycyclic ring system radical havinga conjugated π electron system. Specifically included within thedefinition of “aromatic ring system” are fused ring systems in which oneor more of the rings are aromatic and one or more of the rings aresaturated or unsaturated, such as, for example, fluorene, indane,indene, phenalene, etc. Typical aromatic ring systems include, but arenot limited to, aceanthrylene, acenaphthylene, acephenanthrylene,anthracene, azulene, benzene, chrysene, coronene, fluoranthene,fluorene, hexacene, hexaphene, hexalene, as-indacene, s-indacene,indane, indene, naphthalene, octacene, octaphene, octalene, ovalene,penta-2,4-diene, pentacene, pentalene, pentaphene, perylene, phenalene,phenanthrene, picene, pleiadene, pyrene, pyranthrene, rubicene,triphenylene, trinaphthalene and the like.

“Heteroaromatic Ring System” by itself or as part of another substituentrefers to a aromatic ring system in which one or more carbon atoms (andany associated hydrogen atoms) are independently replaced with the sameor different heteroatom. Typical heteroatoms to replace the carbon atomsinclude, but are not limited to, N, P, O, S, Si, etc. Specificallyincluded within the definition of “heteroaromatic ring systems” arefused ring systems in which one or more of the rings are aromatic andone or more of the rings are saturated or unsaturated, such as, forexample, arsindole, benzodioxan, benzofuran, chromane, chromene, indole,indoline, xanthene, etc. Typical heteroaromatic ring systems include,but are not limited to, arsindole, carbazole, β-carboline, chromane,chromene, cinnoline, furan, imidazole, indazole, indole, indoline,indolizine, isobenzofuran, isochromene, isoindole, isoindoline,isoquinoline, isothiazole, isoxazole, naphthyridine, oxadiazole,oxazole, perimidine, phenanthridine, phenanthroline, phenazine,phthalazine, pteridine, purine, pyran, pyrazine, pyrazole, pyridazine,pyridine, pyrimidine, pyrrole, pyrrolizine, quinazoline, quinoline,quinolizine, quinoxaline, tetrazole, thiadiazole, thiazole, thiophene,triazole, xanthene, and the like.

“Halo” means fluoro, chloro, bromo, or iodo radical.

“Heteroalkyloxy” means an —O-heteroalkyl where heteroalkyl is as definedherein.

“Heteroaryloxycarbonyl” refers to a radical —C(O)—OR where R isheteroaryl as defined herein.

“Substituted” refers to a group in which one or more hydrogen atoms areeach independently replaced with the same or different substituent(s).Typical substituents include, but are not limited to, —X, —R²⁹, —O⁻, ═O,—OR²⁹, —SR²⁹, —S⁻, ═S, —NR²⁹R³⁰, ═NR²⁹, —CX₃, —CF₃, —CN, —OCN, —SCN,—NO, —NO₂, ═N₂, —N₃, —S(O)₂O⁻, —S(O)₂OH, —S(O)₂R²⁹, —OS(O₂)O⁻,—OS(O)₂R²⁹, —P(O)(O⁻)₂, —P(O)(OR²⁹)(O⁻), —OP(O)(OR²⁹)(OR³⁰), —C(O)R²⁹,—C(S)R²⁹, —C(O)OR²⁹, —C(O)NR²⁹R³⁰, —C(O)O⁻, —C(S)OR²⁹, —NR³¹C(O)NR²⁹R³⁰,—NR³¹C(S)NR²⁹R³⁰, —NR³¹C(NR²⁹)NR²⁹R³⁰ and —C(NR²⁹)NR²⁹R³⁰, where each Xis independently a halogen; each R²⁹ and R³⁰ are independently hydrogen,alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substitutedarylalkyl, cycloalkyl, substituted cycloalkyl, cycloheteroalkyl,substituted cycloheteroalkyl, heteroalkyl, substituted heteroalkyl,heteroaryl, substituted heteroaryl, heteroarylalkyl, substitutedheteroarylalkyl, —NR³¹R³², —C(O)R³¹ or —S(O)₂R³¹ or optionally R²⁹ andR³⁰ together with the atom to which they are both attached form acycloheteroalkyl or substituted cycloheteroalkyl ring; and R³¹ and R³²are independently hydrogen, alkyl, substituted alkyl, aryl, substitutedaryl, arylalkyl, substituted arylalkyl, cycloalkyl, substitutedcycloalkyl, cycloheteroalkyl, substituted cycloheteroalkyl, heteroalkyl,substituted heteroalkyl, heteroaryl, substituted heteroaryl,heteroarylalkyl or substituted heteroarylalkyl.

“Sulfonic acids derivatives” as used herein are a class of organic acidradicals with the general formula RSO₃H or RSO₃. An oxygen, suflur, or Rmoiety can serve as a point of attachment. Sulfonic acid saltderivatives substitute a cationic salt (e.g. Na⁺, K⁺, etc.) for thehydrogen on the sulfate group. In various embodiments, the deprotonatedsulfonic acid group can be used as the point of attachment to atherapeutic or targeting group, optionally via a linker. Examples ofsulfonic acid derivatives and include, but are not limited to,2-methyl-2-propane-1-sulfonic acid-sodium salt, 2-sulfoethylmethacrylate, 3-phenyl-1-propene-2-sulfonic acid-p-toluidine salt,3-sulfopropyl acrylate-potassium salt, 3-sulfopropylmethacrylate-potassium salt, ammonium 2-sulfatoethyl methacrylate,styrene sulfonic acid, 4-sodium styrene sulfonate.

“Anhydride derivatives” as used herein refer to a compound or radicalhaving the chemical structure R₁C(O)OC(O)R₂. The carboxyl groups,optionally after removal of R₁ or R₂ groups, can be used as the point ofattachment to a therapeutic or targeting group, optionally via a linker.Examples of anhydride derivatives include, but are not limited to,acrylic anhydride, methacrylic anhydride, maleic anhydride, and4-methacryloxyethyl trimellitic anhydride

“Hydroxyl derivative” as used herein refers to a compound or radicalhaving the structure ROH. The deprotonated hydroxyl group can be used asthe point of attachment to a therapeutic or targeting group, optionallyvia a linker. Example of hydroxyl derivatives include, but are notlimited to, vinyl alcohol, 2-hydroxyethyl acrylate, 2-hydroxyethylmethacrylate, 2-allyl-2-methoxyphenol, divinyl glycol, glycerolmonomethacrylate, poly(propylene glycol)monomethacrylate,N-(2-hydroxypropyl)methacrylamide, hydroxymethyldiacetoneacrylamide,poly(ethylene glycol)monomethacrylate, N-methacryloylglycylglycine,N-methacryloylglycyl-DL-phenylalanylleucylglycine,4-methacryloxy-2-hydroxybenzophenone, 1,1,1-trimethylolpropane diallylether, 4-allyl-2-methoxyphenol, hydroxymethyldiacetoneacrylamide,N-methylolacrylamide, and sugar based monomers.

“Amine derivatives” are compound or radicals thereof having a functionalgroup containing at least one nitrogen, and having the structure RNR′R″.R, R′ and R″ in amine derivatives can each independently be any desiredsubstituent, including but not limited to hydrogen, halides, andsubstituted or unsubstituted alkyl, alkoxy, aryl or acyl groups. “Amidederivatives” as used herein refer to compounds having the structureRC(O)NR′R″. The R, R′ and R″ in amide derivatives can each independentlybe any desired substituent, including but not limited to hydrogen,halides, and substituted or unsubstituted alkyl, alkoxy, aryl or acylgroups. The amine or amide group can be used as the point of attachmentto a therapeutic or targeting group, optionally via a linker. Examplesof amines and amides include, but are not limited to,2-(N,N-diethylamino)ethyl methacrylate, 2-(N,N-diethylamino)ethylacrylate, N-[2-(N,N-dimethylamino)ethyl]methacrylamide,N-[3-(N,N-dimethylamino)propyl]acrylamide, diallylamine,methacryloyl-L-lysine, 2-(tert-butylamino)ethyl methacrylate,N-(3-aminopropyl)methacrylamide hydrochloride, 3-dimethylaminoneopentylacrylate, N-(2-hydroxypropyl)methacrylamide, N-methacryloyl tyrosineamide, 2-diisopropylaminoethyl methacrylate, 3-dimethylaminoneopentylacrylate, 2-aminoethyl methacrylate hydrochloride,hydroxymethyldiacetoneacrylamide, N-(iso-butoxymethyl)methacrylamide andN-methylolacrylamide.

“Silane derivative” as used herein refers to compounds or radicalsthereof having at least one substituent having the structure RSiR′R″R′″.R, R′ and R″ can each independently be any desired substituent,including but not limited to hydrogen, alkyl, alkoxy, aryl or acylgroups. The silane group can be used as the point of attachment to atherapeutic or targeting group, optionally via a linker. Examples ofsilane derivatives include, but are not limited to, 3-methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, 2-(trimethylsiloxy)ethylmethacrylate,1-(2-trimethylsiloxyethoxy)-1-trimethylsiloxy-2-methylpropene

“Phosphate derivatives” as used herein refer to compounds or radicalsthereof having at least one compound containing the structure RR′R″PO₄.R, R′ and R″ can each independently be any desired substituent,including but not limited to hydrogen, alkyl, alkoxy, aryl or acylgroups. The phosphate group can be used as the point of attachment to atherapeutic or targeting group, optionally via a linker. Examples ofphosphate derivatives include, but are not limited to, monoacryloxyethylphosphate and bis(2-methacryloxyethyl)phosphate.

“Nitro derivatives” as used herein refer to compounds or radicalsthereof having an NO₂ group. The nitro group can be used as the point ofattachment to a therapeutic or targeting group, optionally via a linker.Examples include, but are not limited to, o-nitrobenzyl methacrylate,methacryloylglycyl-DL-phenylalanyl-L-leucyl-glycine 4-nitrophenyl ester,methacryloylglycyl-L-phenylalanyl-L-leucyl-glycine 4-nitrophenyl ester,N-methacryloylglycylglycine 4-nitrophenyl ester, 4-nitrostyrene

“Succinimide derivative” as used herein refers to compounds or radicalsthereof having the group

The succinyl R groups can be substituted by any substituent, for exampleand substituted or unsubstituted alkyl, alcoxy, aryl groups. Typically,the succinimide group is attached to a compound via a covalent bond atthe nitrogen. The succinimide group can be used as the point ofattachment to a therapeutic or targeting group, optionally via a linker.A succinimide derivative can be a sulfo-containing succinimidederivative. N-acryloxysuccinimide is an exemplary succinimidederivative.

“Halide derivatives” as used herein refer to compounds or radicalsthereof having a halide substituent. The halide group can be used as thepoint of attachment to a therapeutic or targeting group, optionally viaa linker. Examples include, but are not limited to, vinyl chloride,3-chlorostyrene, 2,4,6-tribromophenyl acrylate, 4-chlorophenyl acrylate,2-bromoethyl acrylate. Non-limiting examples include, but are notlimited to, divinylbenzene, ethylene glycol diacrylate,N,N-diallylacrylamide, and allyl methacrylate.

“Morpholine derivatives” as used herein refer to compounds or radicalsthereof having the structure:

Typically, the amine group serves as the point of attachment to othercompounds. The morpholine group can be used as the point of attachmentto a therapeutic or targeting group, optionally via a linker. Examplesof morpholine derivatives include, but are not limited to,N-acryloylmorpholine, 2-N-morpholinoethyl acrylate and2-N-morpholinoethyl methacrylate.

“Cyano derivatives” as used herein refer to compounds or radicalsthereof having the structure RCN. R can each independently be anydesired substituent. The cyano group can be used as the point ofattachment to a therapeutic or targeting group, optionally via a linker.Examples of cyano derivatives include, but are not limited to,2-cyanoethyl acrylate.

“Epoxide derivatives” as used herein refer to compounds or radicalsthereof having the following chemical structure:

R, R′, R″, and R′″ can each independently be any desired substituent.The epoxide group can be used as the point of attachment to atherapeutic or targeting group, optionally via a linker. Examples ofepoxide derivatives include, but are not limited to, glycidylmethacrylate.

“Ester derivatives” as used herein refer to a compound or a radicalthereof having the generic chemical structure RC(O)OR′. R and R′ caneach independently be any desired substituent. The ester group can beused as the point of attachment to a therapeutic or targeting group,optionally via a linker. Examples include, but are not limited to,methyl acrylate, methyl methacrylate, tert-butyl acrylate, tert-butylmethacrylate, vinyl acetate, benzyl acrylate and benzyl methacrylate.

“Ether derivatives” as used herein refer to a compound or a radicalthereof having the generic chemical structure R—O—R′. The ether groupcan be used as the point of attachment to a therapeutic or targetinggroup, optionally via a linker. Examples include, but are not limitedto, methyl vinyl ether, butyl vinyl ether, 2-chloroethyl vinyl ether,cyclohexyl vinyl ether.

“Carbazole derivatives” as used to herein refer to a compound or radicalthereof having the structure

and any substitutions at any site thereof. The carbazole group can beused as the point of attachment to a therapeutic or targeting group,optionally via a linker. Examples of carbazole derivatives include butare not limited to, N-vinylcarbazole.

“Azide derivatives” as used herein refer to a compound or a radicalthereof having the structure N═N=N. The azide group can be used as thepoint of attachment to a therapeutic or targeting group, optionally viaa linker. Examples of azide derivatives include, but are not limited to,2-hydroxy-3-azidopropyl methacrylate, 2-hydroxy-3-azidopropyl acrylate,3-azidopropyl methacrylate.

The term “maleimide derivative” as referred to herein refers to acompound or a radical thereof having the structure:

R, R′ and R″ can each independently be any desired substituent.

The term “thiolate” refers to a compound or radical thereof having a —SRstructure, where R can be any desired substituent.

The term “thioether” refers to a compound or radical thereof having thestructure R—S—CO—R′, where R and R′ can each independently be anydesired substituent.

The term “thioester” refers to a compound or radical thereof having thestructure R—S—CO—R′, where R and R′ can each independently be anydesired substituent.

The term “carboxylate” refers to a compound or radical thereof havingthe structure RCOO—, where R can be any desired substitutent.

The term “phosphonate” refers to a compound or radical thereof havingthe structure R—PO(OH)₂ or R—PO(OR′)₂ where R and R′ can eachindependently be any desired substituent.

The term “phosphinate” refers to a compound or radical thereof havingthe structure OP(OR)R′R″ where R, R′ and R′ can each independently beany desired substituent.

The term “sulphonate” refers to a compound or radical thereof having thestructure RSO₂O⁻ where R can be any desired substituent.

The term “sulphate” refers to a compound or radical thereof having thestructure RSO₄. where R can be any desired substituent.

A “reducing agent” is an element or a compound that reduces anotherspecies. Exemplary reducing agents include, but are not limited to,ferrous ion, lithium aluminium hydride (LiAlH₄), potassium ferricyanide(K₃Fe(CN)₆), sodium borohydride (NaBH₄), sulfites, hydrazine,diisobutylaluminum hydride (DIBAH), primary amines, and oxalic acid(C₂H₂O₄).

“Treating” or “treatment” of any disease or disorder refers, in someembodiments, to ameliorating the disease or disorder (i.e., arresting orreducing the development of the disease or at least one of the clinicalsymptoms thereof). In other embodiments “treating” or “treatment” refersto ameliorating at least one physical parameter, which may not bediscernible by the patient. In yet other embodiments, “treating” or“treatment” refers to inhibiting the disease or disorder, eitherphysically, (e.g., stabilization of a discernible symptom),physiologically, (e.g., stabilization of a physical parameter), or both.In still other embodiments, “treating” or “treatment” refers to delayingthe onset of the disease or disorder.

The term “antibody” refers to a monomeric or multimeric proteincomprising one or more polypeptide chains that binds specifically to anantigen. An antibody can be a full length antibody or an antibodyfragment.

By “full length antibody” herein is meant the structure that constitutesthe natural biological form of an antibody, including variable andconstant regions. For example, in most mammals, including humans andmice, the full length antibody of the IgG class is a tetramer andconsists of two identical pairs of two immunoglobulin chains, each pairhaving one light and one heavy chain, each light chain comprisingimmunoglobulin domains V_(L) and C_(L), and each heavy chain comprisingimmunoglobulin domains V_(H), CH1 (Cγ1), CH2 (Cγ2), and CH3 (Cγ3). Insome mammals, for example in camels and llamas, IgG antibodies mayconsist of only two heavy chains, each heavy chain comprising a variabledomain attached to the Fc region.

“Antibody fragments” are portions of full length antibodies that bindantigens. Specific antibody fragments include, but are not limited to,(i) the Fab fragment consisting of VL, VH, CL and CH1 domains, (ii) theFd fragment consisting of the VH and CH1 domains, (iii) the Fv fragmentconsisting of the VL and VH domains of a single antibody; (iv) the dAbfragment (Ward et al., 1989, Nature 341:544-546) which consists of asingle variable, (v) isolated CDR regions, (vi) F(ab′)2 fragments, abivalent fragment comprising two linked Fab fragments (vii) single chainFv molecules (scFv), wherein a VH domain and a VL domain are linked by apeptide linker which allows the two domains to associate to form anantigen binding site (Bird et al., 1988, Science 242:423-426, Huston etal., 1988, Proc. Natl. Acad. Sci. U.S.A. 85:5879-5883), (viii)bispecific single chain Fv dimers (PCT/US92/09965) and (ix) “diabodies”or “triabodies”, multivalent or multispecific fragments constructed bygene fusion (Tomlinson et. al., 2000, Methods Enzymol. 326:461-479;WO94/13804; Holliger et al., 1993, Proc. Natl. Acad. Sci. U.S.A.90:6444-6448). In certain embodiments, antibodies are produced byrecombinant DNA techniques. Other examples of antibody formats andarchitectures are described in Holliger & Hudson, 2006, NatureBiotechnology 23(9):1126-1136, and Carter 2006, Nature ReviewsImmunology 6:343-357 and references cited therein, all expresslyincorporated by reference. In additional embodiments, antibodies areproduced by enzymatic or chemical cleavage of naturally occurringantibodies.

Nanoparticles

The present disclosure is directed to modified gold nanoparticles. Theterm “nanoparticle” as referred to herein means a particle includinggold metal organic framework having at least one special dimensionmeasurable less than a micron in length. Nanoparticles includeconventionally known nanoparticles such as nanorods, nanospheres andnanoplatelets. In various embodiments, for example, nanospheres can be arod, sphere, or any other three dimensional shape. Nanoparticles aregenerally described, for example, in Burda et al., Chem. Rev. 2005, 105,1025-1102.

Gold Nanoparticles

Gold nanostructures have architectures which provide tunable opticalproperties. In various embodiments, gold nanoparticles are configuredfor optical imaging techniques. For example, the optical and electronicproperties can be controlled by controlling the size of thenanoparticle, varying the aspect ratio, or rationally assemblingnanorods into a specific shape. Those of skill in the art willunderstand that the size of the gold nanoparticle can be designed tohave specific properties for different applications. For example, thesize of the gold nanoparticle can be designed for colorimeric detection,as described in Martin and Mitchell, Anal. Chem. 1998 pp. 332.Additionally, due to their tunable optical properties, multifunctionalpolymer modified gold nanoparticles can be employed as imaging agentsthrough dark field and confocal microscopy.

Gold nanorods have been used for cancer therapy. Alteration of theirshape and size has proven a useful tool to preferentially kill cancercells through near-infrared lasers and modification with PEG polymershas increased their biocompatibility. Gold nanoparticles may be preparedby methods known in the art, including those disclosed by Burda et al.,Chem. Rev. 2005, 105, 1025-1102 and Daniel and Astruc Chem. Rev. 2004,104, 293-346. Growth methods, including the template, electrochemical,or seeded growth methods, are disclosed by Perez-Juste et al.,Coordination Chemistry Reviews 249 (2005) 1870-1901. Seed particlemethods are further described in Murphy et al. J. Phys. Chem. B 2005,109, 13857-13870. Gold nanoparticles can also be prepared to havespecific surface structures by citrate reduction, two phage synthesisand thiol stabilization, sulfur stabilization, and stabilization withother ligands as described by Daniel and Astruc, Chem. Rev. 2004, 104,293-346.

FIG. 1 depicts TEM images of various exemplary gold nanorod structures.

Forming Initiators on the Nanoparticle Surface

Prior to growing polymers on the surface of Au nanoparticles, thenanoparticle can be treated to form imperfections (or initiators) on thenanoparticle surface that facilitate polymer formation or polymerprecursor binding. Initiating gold nanoparticles may be accomplished bymethods generally known in the art.

FIG. 2 depicts an exemplary protocol in which a gold nanorod is seededas described in Daniel and Astruc, Chem. Rev. 2004. In brief, seeds canbe synthesized via the reduction of gold salts with a strong reducingagent (e.g. NaBH₄) in presence of capping agent (e.g. citrate). Seedsare added to the metal salt in a weak reducing agent (e.g. ascorbicacid) and surfactant-directing agent (e.g. CTAB). The solution is aged16 hours, and the nanoparticles are siphoned and purified viacentrifugation.

FIG. 3 depicts a group of gold nanorods that have been seeded accordingto the method depicted in FIG. 2.

Polymerization

Polymerization can be performed by any method known in the art.Polymerization methods that can be used are described in Principles ofPolymerization, 4th edition (2004) by George Odian, Published byWiley-Interscience, which is incorporated herein by reference in itsentirety. Various methods of polymerization include RAFT, Atom TransferRadical Polymerization (ATRP), Stable Free Radical Polymerization(SFRP), and conventional free radical polymerization.

Reversible addition-fragmentation chain transfer (RAFT) polymerizationoperates on the principle of degenerative chain transfer. Without beinglimited to a particular mechanism, Scheme 1 shows a proposed mechanismfor RAFT polymerization. In Scheme I, RAFT polymerization involves asingle- or multi-functional chain transfer agent (CTA), such as thecompound of formula (I), including dithioesters, trithiocarbonates,xanthates, and dithiocarbamates. The initiator produces a free radical,which subsequently reacts with a polymerizable monomer. The monomerradical reacts with other monomers and propagates to form a chain, Pn*,which can react with the CTA. The CTA can fragment, either forming R*,which will react with another monomer that will form a new chain P_(m)*or P_(n)*, which will continue to propagate. In theory, propagation tothe P_(m)* and P_(n)* will continue until no monomer is left or atermination step occurs. After the first polymerization has finished, inparticular circumstances, a second monomer can be added to the system toform a block copolymer.

RAFT polymerization involves a similar mechanism as traditional freeradical polymerization systems, with the difference of a purposely addedCTA. Addition of a growing chain to a macro-CTA yields an intermediateradical, which can fragment to either the initial reactants or a newactive chain. With a high chain transfer constant and the addition of ahigh concentration of CTA relative to conventional initiator, synthesisof polymer with a high degree of chain-end functionality and with welldefined molecular weight properties is obtained. In certain embodiments,a dithioester, xanthate, dithiocarbamate, or trithiocarbonate group isreduced to produce a thiol or thiolate, which has provided a successfulroute of RAFT polymer attachment to gold surfaces.

In particular embodiments, RAFT polymerization is used to produce avariety of well-defined, novel polymers that either are polymerized fromthe surface of the nanoparticles, or are polymerized and then attachedto the surface of the nanoparticle. RAFT polymerization shows greatpromise in the synthesis of multifunctional polymers due to theversatility of monomer selection and polymerization conditions, alongwith the ability to produce well-defined, narrow polydispersity polymerswith both simple and complex architectures. The flexibility of RAFTpolymerizations makes it an ideal candidate to produce well-definedpolymer structures with a high degree of functionality capable ofproviding increased therapeutic/targeting agent loading and loadingefficiency. For example, RAFT can be successfully used to producewell-defined activated biocopolymer constructs withN-acryloxysuccinimide (NAOS) pendant functionalities. The succinimideside groups have allowed covalent conjugation of bioactive agents suchas fluorescent tags, nucleotides, peptides, and antibodies.Incorporation of NAOS into copolymers provides a route of manipulatingloading efficiency and stability of bioactive agents. Additionaltailoring of the copolymer conjugate system with tumor targeting ortherapeutic agents allows specific localization and treatment to beachieved increasing in vivo performance.

Polymers synthesized by RAFT include chain transfer agents (CTAs). Asused herein, a RAFT chain transfer agent is defined as having thechemical structure of Formula (V):

CTAs agents possessing the thiocarbonylthio moiety, impart reactivity tofree-radical polymerization due to the facile nature of radical additionto C═S bonds which contributes to faster chain equilibration in thechain transfer step. The transfer constants of RAFT CTAs depend on the Zand R substituents. In certain embodiments, the Z group is a freeradical stabilizing species to ensure rapid addition across the C═Sbond.

In certain embodiments, the R group is chosen so that it possesses anequal or greater ability to leave as compared to the addition species.It is also of importance that the R group be able to reinitiate thepolymerization after fragmentation. In certain embodiments, R canfragment from the intermediate quickly and is able to re-initiatepolymerization effectively.

Exemplary CTAs include, but are not limited to, cumyl dithiobenzoate(CDTB) and S-1-Dodecyl-S′-(α,α′-dimethyl-α″-acetic acid)trithiocarbonate(DATC).

Grafting Polymers and Polymer Precursors to Nanoparticles

In certain aspects, polymers can be grafted to the gold nanoparticlesafter polymerization. Desired choice of CTA structures of formula (I)allows for control of the polymerization. The Z group activates thethio-carbonyl (C═S) group for radical addition and allows for theradical intermediate to be stabilized in the transition state.

Schemes 2 and 3 show grafting trithiocarbonate and dithioester RAFTagents to the surface of a gold nanoparticle with or without the use ofa reducing agent. Scheme 2 shows first RAFT polymerization of the alkenein the presence of the trithiocarbonate, and Scheme 3 shows a first stepof RAFT polymerization of the alkene in the presence of the dithioester.

The RAFT polymer is grafted to the surface of the nanoparticle. Withoutbeing limited to any particular mechanism, the nanoparticle iscovalently grafted to the nanoparticle surface. The reduced polymer iscovalently grafted to the nanoparticle.

In Schemes 2 and 3, R₁, R₂, R₃, and R₄ are each independently selectedfrom hydrogen, alkyl, substituted alkyl, alkoxy, substituted alkoxy,acyl, substituted acyl, acylamino, substituted acylamino, alkylamino,substituted alkylamino, alkylsulfinyl, substituted alkylsulfinyl,alkylsulfonyl, substituted alkylsulfonyl, alkylthio, substitutedalkylthio, alkoxycarbonyl, substituted alkoxycarbonyl, aryl, substitutedaryl, arylalkyl, substituted arylalkyl, aryloxy, substituted aryloxy,aryloxycarbonyl, substituted aryloxycarbonyl, carbamoyl, substitutedcarbamoyl, cycloalkyl, substituted cycloalkyl, cycloheteroalkyl,substituted cycloheteroalkyl, dialkylamino, substituted dialkylamino,halo, heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, heteroarylalkyl, substituted heteroarylalkyl,heteroalkyloxy, substituted heteroalkyloxy, heteroaryloxy andsubstituted heteroaryloxy.

Specific examples of RAFT polymers attached to the surface of the goldparticles after polymerization is depicted in Schemes 4 and 5 below.

Scheme 4 depicts a method of attaching a derivatized polymer to a goldnanoparticle after reduction of the trithiocarbonate to produce a goldnanoparticle conjugate.

Grafting from Nanoparticles

In the two examples of generalized RAFT polymerization described abovein Schemes 2 and 3, as well as the specific example in Scheme 4,polymerization occurs prior to grafting to the gold nanoparticle surface(i.e. “grafting to” the nanoparticle surface).

Alternatively, the RAFT polymerization may be accomplished aftergrafting a polymer precursor, initiator, or CTA to the nanoparticlesurface. Scheme 5 depicts attachment of a CTA to a surface-bound RAFTpolymerization. In brief, a polymer precursor is grafted to the surfaceof the nanoparticle. A CTA is attached to the terminus of the polymerprecursor in Step 1. RAFT polymerization is then accomplished in Step 2directly from the surface of the gold nanoparticle, as described, forexample, in Rowe-Konopacki, M. D. and Boyes, S. G. Synthesis of SurfaceInitiated Diblock Copolymer Brushes from Flat Silicon SubstratesUtilizing the RAFT Polymerization Technique. Macromolecules, 40 (4)879-888, 2007, and Rowe, M. D.; Hammer, B. A. G.; Boyes, S. G. Synthesisof Surface-Initiated Stimuli-Responsive Diblock Copolymer BrushesUtilizing a Combination of ATRP and RAFT Polymerization Techniques.Macromolecules, 41 (12), 4147-4157, 2008.

In Scheme 5, n is an integer, and X, R, R₁, R₂, R₃ and R₄ are eachindependently selected from hydrogen, alkyl, substituted alkyl, alkoxy,substituted alkoxy, acyl, substituted acyl, acylamino, substitutedacylamino, alkylamino, substituted alkylamino, alkylsulfinyl,substituted alkylsulfinyl, alkylsulfonyl, substituted alkylsulfonyl,alkylthio, substituted alkylthio, alkoxycarbonyl, substitutedalkoxycarbonyl, aryl, substituted aryl, arylalkyl, substitutedarylalkyl, aryloxy, substituted aryloxy, carbamoyl, substitutedcarbamoyl, cycloalkyl, substituted cycloalkyl, cycloheteroalkyl,substituted cycloheteroalkyl, dialkylamino, substituted dialkylamino,halo, heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, heteroarylalkyl, substituted heteroarylalkyl,heteroalkyloxy, substituted heteroalkyloxy, heteroaryloxy andsubstituted heteroaryloxy. In certain embodiments, X is a halide such asfluorine, bromine, chlorine and iodine. A specific example of thereaction of Scheme 5 is depicted in Scheme 6.

R₃ and R₄ are each independently selected from hydrogen, alkyl,substituted alkyl, alkoxy, substituted alkoxy, acyl, substituted acyl,acylamino, substituted acylamino, alkylamino, substituted alkylamino,alkylsulfinyl, substituted alkylsulfinyl, alkylsulfonyl, substitutedalkylsulfonyl, alkylthio, substituted alkylthio, alkoxycarbonyl,substituted alkoxycarbonyl, aryl, substituted aryl, arylalkyl,substituted arylalkyl, aryloxy, substituted aryloxy, aryloxycarbonyl,substituted aryloxycarbonyl, carbamoyl, substituted carbamoyl,cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substitutedcycloheteroalkyl, dialkylamino, substituted dialkylamino, halo,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, heteroarylalkyl, substituted heteroarylalkyl,heteroalkyloxy, substituted heteroalkyloxy, heteroaryloxy andsubstituted heteroaryloxy.

Grafting from the surface of the nanoparticle as depicted above allowsformation of a “brush” configuration of polymers. With reference to FIG.11, polymers attached to a gold surface can be spaced differently on asurface. Without wishing to be held to a specific theory or mechanism ofaction, the accessibility of the therapeutic agents and targeting agentsto the surrounding environment can be at least partially controlled byhow closely together the polymers are spaced on the surface of thenanoparticle. When the distance between the polymers is greater than thelength of the polymer, the polymers adopt a “mushroom” configuration inwhich the entirety of the polymer can be accessible to surroundingenvironment, including the binding site of a targeting agent ortherapeutic agent attached to the polymer. Conversely, when the distancebetween the polymer chains is shorter than the attached polymer, thepolymers have a brush conformation, in which the terminal portions ofthe polymer are accessible to the surrounding environment. If thetherapeutic and/or targeting agents are attached to the terminus of thepolymers arranged in a “brush” conformation, then the therapeutic and/ortargeting agents can be accessible to the surrounding environment.

Desired polymer configuration on the surface can be achieved by growingthe polymers from the surface of the nanoparticle. In certain aspects,the polymerization is initiated directly from substrate via immobilizedinitiators. The brush polymer conformation can be achieved by formingthe polymer from the nanoparticle surface, or alternatively by utilizingseparately or combining atom transfer radical polymerization (ATRP) andRAFT polymerization. Growing the polymers from the surface allowsimmobilized polymerization initiators to be tailored for a wide range ofpolymerization techniques and substrates.

In particular, synthesizing polymer brushes requires control of thepolymer molecular weight (i.e. brush thickness), narrow polydispersitiesand control of the composition. In the two examples of generalized RAFTpolymerization described above in Schemes 6 and 7, polymerization occursprior to grafting to the gold nanoparticle surface (i.e. “grafting to”the nanoparticle surface).

Functional Groups

Functional groups are groups that can be covalently linked to thepolymer and covalently linked to the therapeutic or targeting agents,and/or bonded to the nanoparticles. The functional groups include anygroup that can be reacted with another compound to form a covalentlinkage between the compound and the polymer extending from thenanoparticle. Exemplary functional groups can include carboxylic acidsand carboxylic acid salt derivatives, acid halides, sulfonic acids andsulfonic acid salts, anhydride derivatives, hydroxyl derivatives, amineand amide derivatives, silane derivations, phosphate derivatives, nitroderivatives, succinimide and sulfo-containing succinimide derivatives,halide derivatives, alkene derivatives, morpholine derivatives, cyanoderivatives, epoxide derivatives, ester derivatives, carbazolederivatives, azide derivatives, alkyne derivatives, acid containingsugar derivatives, glycerol analogue derivatives, maleimide derivatives,protected acids and alcohols, and acid halide derivatives. Thefunctional groups can be substituted or unsubstituted, as describedherein.

Functional groups can be attached to the polymer during polymerizationas depicted herein.

Alternatively, functional groups can be attached to the polymer backbonevia a linker. The term “linker” as used herein refers to any chemicalstructure that can be placed between the polymer and functional group.For example, linkers include a group including alkyl, substituted alkyl,alkoxy, substituted alkoxy, acyl, substituted acyl, acylamino,substituted acylamino, alkylamino, substituted alkylamino,alkylsulfinyl, substituted alkylsulfinyl, alkylsulfonyl, substitutedalkylsulfonyl, alkylthio, substituted alkylthio, alkoxycarbonyl,substituted alkoxycarbonyl, aryl, substituted aryl, arylalkyl,substituted arylalkyl, aryloxy, substituted aryloxy, carbamoyl,substituted carbamoyl, cycloalkyl, substituted cycloalkyl,cycloheteroalkyl, substituted cycloheteroalkyl, dialkylamino,substituted dialkylamino, halo, heteroalkyl, substituted heteroalkyl,heteroaryl, substituted heteroaryl, heteroarylalkyl, substitutedheteroarylalkyl, heteroalkyloxy, substituted heteroalkyloxy,heteroaryloxy and substituted heteroaryloxyalkyl groups. In variousnon-limited exemplary embodiments, the groups can be from C1 to C10,C20, or C30.

In various embodiments, the linker can include a conjugated bond,preferably selected from acetylene (—C═C—, also called alkyne orethyne), alkene (—CH═CH—, also called ethylene), substituted alkene(—CR═CR—, —CH═CR— and —CR═CH—), amide (—NH—CO— and —NR—CO— or —CO—NH—and —CO—NR—), azo (—N═N—), esters and thioesters (—CO—O—, —O—CO—, —CS—O—and —O—CS—) and other conjugated bonds such as (—CH═N—, —CR═N—, —N═CH—and —N═CR—), (—SiH═SiH—, —SiR═SiH—, —SiR═SiH—, and —SiR═SiR—),(—SiH═CH—, —SiR═CH—, —SiH═CR—, —SiR═CR—, —CH═SiH—, —CR═SiH—, —CH═SiR—,and —CR═SiR—). Particularly certain bonds are acetylene, alkene, amide,and substituted derivatives of these three, and azo. The linker couldalso be carbonyl, or a heteroatom moiety, wherein the heteroatom isselected from oxygen, sulfur, nitrogen, silicon or phosphorus. Thus,suitable heteroatom moieties include, but are not limited to, —NH and—NR, wherein R is as defined herein; substituted sulfur; sulfonyl(—SO₂—) sulfoxide (—SO—); phosphine oxide (—PO— and —RPO—); andthiophosphine (—PS— and —RPS—). The linker could also be a peptidylspacer such as Gly-Phe-Leu-Gly.

Therapeutic Agents and Targeting Agents

Targeting agents and therapeutic agents can be covalently attached tothe polymer. FIG. 13 shows exemplary targeting molecules (folic acid oran RGD sequence) and exemplary therapeutic agents (the cancertherapeutics paclitaxel or methotrexate) binding to a functionalizedpolymer grafted to a nanoparticle. The functional groups attach to thepolymer backbone by reaction with the succinimide functional group.Conjugation of therapeutic, targeting, and imaging agents to thecopolymer provides a multifaceted system, which has potential indecreasing toxicity while increasing efficacy of the drug due todirected treatment through directed targeting with the ability to imagethrough optical, magnetic resonance, or computer tomography.

It will be understood by those of skill in the art that varioustargeting agents or therapeutic agents can be selected for attachment tofunctional groups. Further, it will be understood that a linker can beplaced between the functional groups and the targeting agents andtherapeutic agents. The linker can be cleavable or non-cleavable. Forexample, in certain instances therapeutic agents can be cleavable. Incertain instances, diagnostic agents can be non-cleavable.

Targeting agents are compounds with a specific affinity for a targetcompound, such as a cell surface epitope associated with a specificdisease state. Targeting agents may be attached to a nanoparticlesurface to allow targeting of the nanoparticle to a specific target.Non-limiting examples of targeting agents include an amino acid sequenceincluding the RGD peptide, an NGR peptide, folate, Transferrin, GM-CSF,Galactosamine, peptide linkers including growth factor receptors (e.g.IGF-1R, MET, EGFR), antibodies and antibody fragments includinganti-VEGFR, Anti-ERBB2, Anti-tenascin, Anti-CEA, Anti-MUC1, Anti-TAG72,mutagenic bacterial strains, and fatty acids.

In various embodiments, targeting agents can be chosen for the differentways in which they interact with tumors. For example, when the targetingagent folic acid is taken into the cells by the folate receptors, RGDreceptors are expressed on the surface of the cells, resulting in thenanostructures localizing to the cell surface. The folate receptor isknown to be over expressed in cancer cells in the case of epithelialmalignancies, such as ovarian, colorectal, and breast cancer, whereas inmost normal tissue it is expressed in very low levels.

Therapeutic agents include any therapeutic compounds that are capable ofpreventing or treating a disease in a patient. Numerous therapeuticagents are known in the art. Non-limiting examples of therapeutic agentsinclude doxorubicin, paclitaxel, methotrexate, cisplatin, camptothecin,vinblastine, aspartic acid analogues, and short interfering ribonucleicacid (siRNA) molecules.

Therapeutic agents and targeting agents can be covalently attached tothe polymer by RAFT synthesis. The therapeutic agent or targeting agentis configured to be added to the RAFT polymer during polymerization. Assuch the therapeutic agent and targeting agent can be linked directly tothe RAFT polymer. Those of skill in the art will recognize that a linkercan be added between the therapeutic agent or targeting agent and thepolymer.

Alternatively, therapeutic agents and targeting agents are linked to thepolymer via a functional group as described above. Those of skill in theart will recognize that a linker can be added between the therapeuticagent or targeting agent and the polymer.

Multifunctional synthesis of compounds can be accomplished by RAFTpolymerization as depicted in the example of Scheme 7.

In this embodiment, a succinimide group can be used to attach afunctional group to the nanoparticle. An example of biocompatiblecopolymers containing functional N-acryloyloxysuccinimide (NAOS) monomerunits can also be synthesized via RAFT polymerization. A range ofcopolymer backbones can be used, including, but not limited to,N-isopropylacrylamide (NIPAM), N,N-dimethylaminoethyl acrylate (DMAEA),and poly(ethylene glycol)methyl ether acrylate (PEGMEA). The addition ofNAOS into the copolymer backbones has been achieved at a range of weightpercents as a means of attachment. The copolymers were synthesizedutilizing the well-known trithiocarbonate DATC in dioxane at 60 or 70degrees, with a fluorescein monomer incorporated near the end of thepolymerization. The polymers were characterized via both proton NMR andGPC.

In various embodiments, unreacted succinimide groups can further beconverted to non-bioactive groups to reduce in vivo side reactions.

In Scheme 8, a folic acid targeting agent is attached to the succinimidefunctional group.

FIG. 10 a depicts a ¹H NMR spectrum of PNIPAM-co-PNAOS-co-PFMAcopolymer. FIG. 10 b depicts a 1H NMR spectrum of folic acid. FIG. 10 cdepicts a 1H NMR spectrum of PNIPAM copolymer reacted with folic acid.

Other Methods

Aside from the in vivo diagnosis and treatment of cancer, withattachment of appropriate therapeutics and/or targeting moieties, theinvention maybe used for a wide variety of different drug deliveryapplications, such as gene therapy, imaging applications, such asvascular imaging, and even in external molecular detection devices, suchas microarrays and assays. The primary industry interested in theinvention would be pharmaceutical companies. While these applicationshave been mentioned specifically there may be many more applicationsthat the inventors have not considered or are yet to be thought of forthe invention.

EXAMPLES

The following examples are intended to be exemplary, and not limit, thepresent disclosure.

Example 1

FIG. 4 depicts a comparison absorbance spectrum of A) gold nanorods, B)gold nanorods modified with the strong reducing agent sodium borohydrideand poly(acrylic acid) (PAA) and C) gold nanorods modified with PAA andwithout sodium borohydride. In this case the peak of most interest isthe peak center around 530 nm which is due to the transverse surfaceplasmon band of the gold nanorods. Murphy and co-workers have shown thatred-shifts in this peak an indicative of changes in the local refractiveindex around the rods, as occurs when polymer is adsorbed to thesurface. Furthermore, the peak wavelength shift is highly sensitive tothe amount of material adsorbed to the surface, thus UV-vis spectroscopyis a useful tool in monitoring the coating of the gold nanorods with theRAFT polymers.

There are three curves in this spectrum. The first of these is the redcurve which is the absorption spectrum for the plain, washed goldnanorods, with a maximum around 526 nm. Upon coating the nanorods withRAFT generated PAA that has been reduced with NaBH (the red curve), wesee an increase in the maximum absorption to 531 nm, which is consistentwith adsorption of PAA to the surface of the gold nanorods. Thethickness as determined by TEM was approximately 14 nm. FIGS. 5 a and 5b depict TEM images of gold nanorod modified by PAA after treatment withsodium borohydride and without sodium borohydride.

Example 2

FIG. 6 depicts a comparison absorbance spectrum of A) gold nanorods, B)gold nanorods modified with the strong reducing agent sodium borohydrideand (PMMA)-b-poly(2-(dimethylamino)ethyl methacrylate), and C) goldnanorods modified with PDMAEMA and without sodium borohydride. Theabsorption maximum for the transverse surface plasmon band of theungrafted nanorods occurs at a wavelength of 526 nm. Upon coating thegold nanorods with PDMAEMA there is a small red shift in the transversesurface plasmon band of 528 nm when reducing agent was used and 529 nmwhen it was not used. The increase in wavelength seen upon coating thenanorods with the PDMAEMA relates closely to the average thickness ofthe PDMAEMA surrounding the nanorods, which is approximately 3 nm, asdetermined by TEM, in both cases. This corresponds well with theobservations of Gole and Murphy, who demonstrated that the nm increasein the wavelength of the transverse surface plasmon band matched the nmthickness of polyelectrolyte adsorbed to the surface of gold nanorods.It should also be mentioned that there appears to be little, if any,broadening of the surface plasmon band peak, which indicates thataggregation upon grafting of the polymer to the surface of the nanorodsdoes not occur.

FIGS. 7 a and 7 b depict TEM images of a gold nanorod modified byPDMAEMA after treatment with sodium borohydride and without sodiumborohydride.

Example 3

FIG. 8 depicts a comparison absorbance spectrum of A) gold nanorods, B)gold nanorods modified with the strong reducing agent sodium borohydrideand polystyrene (PS) and C) gold nanorods modified with PS and withoutsodium borohydride. TEM micrographs demonstrate that PS is grafted tothe surface of the gold nanorods regardless whether reducing agent isused or not. The TEM images indicates an average PS thickness of 3 nmsurrounding the nanorod when lithium aluminium hydride (LiAlH₄) reducingagent is used versus an 8 nm thickness found when it is not used.UV-Visible spectroscopy was used to verify a red-shift in the transversesurface plasmon band maxima for the samples.

The uncoated purified gold nanorods show an absorption maximum of 531 nmwhen RAFT generated PS is grafted to the surface. The absorption maximashift upward to 534 nm when the LiAlH₄ reducing agent was used and to540 nm when no reducing agent was used. The shifts in the absorptionmaxima for the transverse surface plasmon band correspond closely to thenm thicknesses seen in the TEM images. There also appears to be littleto no peak broadening of the surface absorption maxima, suggesting thataggregation is not occurring.

FIGS. 9 a and 9 b show TEM images of a gold nanorod modified by PDMAEMAafter treatment with sodium borohydride and without sodium borohydride.

Example 4

Gold nanorods were synthesized via a three-step seed-mediated approach,providing a good concentration of nanorods with an average length of 300nm and average diameter of 25 nm. Gold nanorods have been successfullymodified using the PNIPAM-co-PNAOS(@25% wt)-co-PFMA copolymersynthesized via RAFT polymerization, where the trithiocarbonate endgroups were utilized for immobilization of chains onto the gold nanorodsurfaces. Transmission electron microscopy (TEM) images confirm theformation of a relatively uniform film around the entirety of the goldnanorod structure with an average thickness of 6 nm. In combination withTEM, UV-Vis was employed to characterize the virgin nanoparticles. Thegold nanorods showed two main absorption maxima, the first at ˜525 nmand are attributed to the transverse surface plasmon resonanceabsorption band. The second at a higher wavelength characteristic of thelongitudinal surface plasmon band. UV-Vis verifies immobilization with acomparative red shift in the absorption maxima of the transverse surfaceplasmon from 520 nm to 527 nm. Additionally, the 7 nm red shift in theUV-Vis directly correlates with the thickness of the polymer coatingseen in TEM.

The succinimide functionality has been subsequently modified throughcondensation reactions to attach an assortment of tumor targeting and/ortherapeutic agents, such as folic acid, GRGD sequences, Paclitaxel, andMethotrexate. For example, the PNIPAM-co-PNAOS(@25% wt)-co-PFMA wasmodified by the addition of folic acid through a condensation reactionwith the NAOS functionality and a readily accessible primary amine offolic acid. Folic acid has been shown to specifically targetover-expressed folate receptors on the periphery of epithelial malignantcancer cells, such as ovarian, colorectal, and breast cancer cells.

Example 5

The ability of nanoparticles to inhibit in vitro was measured. A rangeof samples including virgin gold nanorods, PNIPAM-co-PNAOS(25%wt)-co-PFMA, PDMAEA-co-PNAOS(25% wt)-co-PFMA, andPPEGMEA-co-PNAOS(@17%)-co-PFMA copolymers, along with gold nanorodsmodified with PNIPAM-co-PNAOS-co-PFMA copolymer have been studied.Canine osteosarcoma cells were initially used as a proof of conceptstudy and the systems were incubated at physiological temperature, 37°C. for 72 hours in a 5% CO₂ atmosphere. Preliminary growth inhibitioncurves for nanoparticles, unmodified polymers, and polymer modifiednanoparticles confirm that none of the compounds show a significantanti-proliferative or cytotoxic effect on the incubated cancer cells.

A range of therapeutic agents and targeting agents were tested forefficacy following post-polymerization covalent attachment of thePNIPAM-co-PNAOS(@25% wt)-co-PFMA copolymer with the agents. Testedtherapeutic agents included Paclitaxel and Methotrexate. Targetingagents include folic acid and GRGD sequences. Samples were incubatedwith CTAC and FITZ at physiological temperature for 4, 24, and 72 hoursin a 5% CO₂ atmosphere. These cells lines chosen based on theirsusceptibility to the therapeutic agents being tested, along withtargeting ability through the GRGD sequences.

Applicants further note that the compounds and methods disclosed hereininclude those compounds cited in U.S. 2007/0123670 to McCormick et al.,which is incorporated herein by reference in its entirety.

All references cited herein are incorporated herein by reference intheir entirety.

What is claimed is:
 1. A method of making a gold nanoparticle conjugatecomprising: contacting a trithiocarbonate of the following formula

with an alkene of the following formula

to produce a polymer of the following formula

and contacting the polymer with a gold nanoparticle to form the goldnanoparticle conjugate, wherein R₁, R₂, R₃, and R₄ are eachindependently selected from hydrogen, alkyl, substituted alkyl, alkoxy,substituted alkoxy, acyl, substituted acyl, acylamino, substitutedacylamino, alkylamino, substituted alkylamino, alkylsulfinyl,substituted alkylsulfinyl, alkylsulfonyl, substituted alkylsulfonyl,alkylthio, substituted alkylthio, alkoxycarbonyl, substitutedalkoxycarbonyl, aryl, substituted aryl, arylalkyl, substitutedarylalkyl, aryloxy, substituted aryloxy, aryloxycarbonyl, substitutedaryloxycarbonyl, carbamoyl, substituted carbamoyl, cycloalkyl,substituted cycloalkyl, cycloheteroalkyl, substituted cycloheteroalkyl,dialkylamino, substituted dialkylamino, halo, heteroalkyl, substitutedheteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl,substituted heteroarylalkyl, heteroalkyloxy, substituted heteroalkyloxy,heteroaryloxy and substituted heteroaryloxy.
 2. The method of claim 1,wherein the gold nanoparticle conjugate has the following formula

represents the surface of the gold nanoparticle.
 3. The method of claim1, wherein the trithiocarbonate and alkene are contacted undernon-reducing conditions.
 4. The method of claim 1, wherein the polymerand gold nanoparticle are contacted under non-reducing conditions. 5.The method of claim 1, wherein the polymer and gold nanoparticle areassociated through more than one sulfur atom.
 6. The method of claim 1,wherein the gold nanoparticle conjugate further comprises a functionalgroup.
 7. The method of claim 6, wherein the functional group isselected from the group consisting of carboxylic acids and carboxylicacid salt derivatives, acid halides, sulfonic acids and sulfonic acidsalts, anhydride derivatives, hydroxyl derivatives, amine and amidederivatives, silane derivations, phosphate derivatives, nitroderivatives, succinimide and sulfo-containing succinimide derivatives,halide derivatives, alkene derivatives, morpholine derivatives, cyanoderivatives, epoxide derivatives, ester derivatives, carbazolederivatives, azide derivatives, alkyne derivatives, acid containingsugar derivatives, glycerol analogue derivatives, maleimide derivatives,protected acids and alcohols, and acid halide derivatives.
 8. The methodof claim 1, wherein the gold nanoparticle conjugate further comprises atherapeutic agent covalently bonded to the polymer.
 9. The method ofclaim 1, wherein the gold nanoparticle conjugate further comprises atargeting agent covalently bonded to the polymer.
 10. A method of makinga gold nanoparticle conjugate comprising: contacting a compound of thefollowing formula

with an alkene of the following formula

to produce a polymer of the following formula

and contacting the polymer with a gold nanoparticle to form the goldnanoparticle conjugate, wherein R₁, R₂, R₃, and R₄ are eachindependently selected from hydrogen, alkyl, substituted alkyl, alkoxy,substituted alkoxy, acyl, substituted acyl, acylamino, substitutedacylamino, alkylamino, substituted alkylamino, alkylsulfinyl,substituted alkylsulfinyl, alkylsulfonyl, substituted alkylsulfonyl,alkylthio, substituted alkylthio, alkoxycarbonyl, substitutedalkoxycarbonyl, aryl, substituted aryl, arylalkyl, substitutedarylalkyl, aryloxy, substituted aryloxy, aryloxycarbonyl, substitutedaryloxycarbonyl, carbamoyl, substituted carbamoyl, cycloalkyl,substituted cycloalkyl, cycloheteroalkyl, substituted cycloheteroalkyl,dialkylamino, substituted dialkylamino, halo, heteroalkyl, substitutedheteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl,substituted heteroarylalkyl, heteroalkyloxy, substituted heteroalkyloxy,heteroaryloxy and substituted heteroaryloxy.
 11. The method of claim 10,wherein the compound is a dithioester, xanthate, or dithiocarbamate. 12.The method of claim 10, wherein the gold nanoparticle conjugate has thefollowing formula

represents the surface of the gold nanoparticle.
 13. The method of claim10, wherein the compound and alkene are contacted under non-reducingconditions.
 14. The method of claim 10, wherein the polymer and goldnanoparticle are contacted under non-reducing conditions.
 15. The methodof claim 10, wherein the polymer and gold nanoparticle are associatedthrough more than one sulfur atom.
 16. The method of claim 10, whereinthe gold nanoparticle conjugate further comprises a functional group.17. The method of claim 16, wherein the functional group is selectedfrom the group consisting of carboxylic acids and carboxylic acid saltderivatives, acid halides, sulfonic acids and sulfonic acid salts,anhydride derivatives, hydroxyl derivatives, amine and amidederivatives, silane derivations, phosphate derivatives, nitroderivatives, succinimide and sulfo-containing succinimide derivatives,halide derivatives, alkene derivatives, morpholine derivatives, cyanoderivatives, epoxide derivatives, ester derivatives, carbazolederivatives, azide derivatives, alkyne derivatives, acid containingsugar derivatives, glycerol analogue derivatives, maleimide derivatives,protected acids and alcohols, and acid halide derivatives.
 18. Themethod of claim 10, wherein the gold nanoparticle conjugate furthercomprises a therapeutic agent covalently bonded to said polymer.
 19. Themethod of claim 10, wherein the gold nanoparticle conjugate furthercomprises a targeting agent covalently bonded to said polymer.